<!DOCTYPE html>
<html>
<head>
<style>
div { border:1px solid; }
</style>
</head>
<body>

<div style="font-size:16px; width:160px">
font-size:16px; width:160px
</div>

<div style="font-size:16px; width:10em">
font-size:16px; width:10em
</div>

<div style="font-size:1em; width:10em">
font-size:1em; width:10em
</div>

<div style="font-size:16px; width:120pt">
font-size:16px; width:120pt
</div>

<div>
<img src="http://www.google.com/intl/en_ALL/images/logo.gif">
</div>

</body>
</html>